Hmmm what's stopping someone from hacking Trump's twitter account and announcing things that would swing the stock market? "I am now placing sanctions on the B

Hmmm what's stopping someone from hacking Trump's twitter account and announcing things that would swing the stock market? "I am now placing sanctions on the Bank of China and PetroChina for North Korean oil sales" "I am now announcing Magnitsky sanctions on [insert Central Committee members here] for Xinjiang" "The whole country of China is now subject to technology sanctions" "I am now placing tariffs on German cars until Germany cancels Nord Stream" "I am banning US companies who source components from China from participating in federal contracts" or even positive news like "Tomorrow, my great friend Xi Jinping and I will announce a wonderful deal with China that lifts all tariffs, solves IP issues, and lets our great economy invest in theirs and vice versa"